1. Field of the Invention
The present invention relates to recording data on an optical recording medium, and more particularly, to a method of detecting a phase difference between an address information signal and a wobble signal of an optical recording medium, and controlling a correction of the obtained phase difference.
2. Description of the Related Art
Generally, optical recording media such as a DVD-R and a DVD-RW have land pre-pits (LPPs) which are formed by providing pits having address information on a land during a manufacturing thereof. An LPP signal is read where a light beam follows a track of an optical recording medium. The LPP signal is measured by an optical pickup of a recording apparatus before and after a recording.
A groove wobble is also read where a light beam follows a track, and is measured by an optical pickup of a recording apparatus before and after a recording.
Where a groove wobble signal is a sine wave signal, the groove wobble signal and an LPP signal are formed on a disc such that the two signals have a phase difference of 90±10°. The difference between the groove wobble signal and the LPP signal is measured between the highest point of the LPP signal and the average zero crossing point of the groove wobble signal. This phase difference should be maintained so that the LPP signal can be correctly decoded and data can be recorded on accurate locations on the optical recording medium.
Where a wobble signal and an LPP signal are detected, the characteristic of a detection filter itself increases the phase difference such that an accurate phase difference between the wobble signal and LPP signal cannot be obtained.
In the optical recording media such as a DVD-R and a DVD-RW, address information is engraved on the disc by using phase information of a wobble signal. Where the wobble signal is detected and compared with a phase reference signal, a wobble phase error generated by the characteristic of a detection filter itself should be corrected so as to record data on accurate locations on the optical recording medium.